Overvoltage arrester with ejectable type ground line

ABSTRACT

An overvoltage arrester has a diaphragm which seals the interior of the housing thereof and a deflection plate for gases which may escape during an overloading of the arrester, upon the rupture of the diaphragm. The ground line of the arrester is affixed to the deflection plate by an ejectable resilient body constructed of cup-shaped sheet metal part and mounted in the deflection plate in operative proximity with the diaphragm.

llnited States Patent [191 Schmalz et al.

[4 1 Apr.9,l1974 1 OVERVOLTAGE ARRESTER WITH EJECTABLE TYPE GROUND LINE [75] Inventors: Gustav Schmalz, Berlin; Wolfgang Werner, Erlangen, both of Germany [73] Assignee: Siemens Aktie'ngesellschaft, Berlin,

Germany 22 Filed: Nov. 9, 1971 211 App]. No.: 196,906

[30] Foreign Application Priority Data Nov. 12, 1970 Germany 2056526 [52] U.S. Cl 337/28, 337/32, 337/203,

' 337/250 [51] Int. Cl. H01h 85/30, HOlh 85/58 [58] Field of Search 337/28-34,

[56] References Cited 8 UNITED STATES PATENTS 2,640,096 5/1953 Kalb .l ..3l7/68 3,153,128 10/1964 Corothers 337/33 3,586,914 6/1971 Foitzik ..317/68 Primary ExaminerRoy N. Envall, Jr. Attorney, Agent, or Firm-Arthur E. Wilfond [5 7 ABSTRACT An overvoltage arrester has a diaphragm which seals the interior of the housing thereof and a deflection plate for gases which may escape during an overloading of the arrester, upon the rupture of the diaphragm. The ground line of the arrester is affixed to the deflection plate by an ejectable resilient body constructed of cup-shaped sheet metal part and mounted in the deflection plate in operative proximity with the diaphragm.

5 Claims, 1 Drawing Figure OVERVOILTAGE ARRESTER WllTll1 EJECTABLE TYPE GROUND LINE The invention relates to an overvoltage or lightning arrester. More particularly, the invention relates to an overvoltage arrester with an ejectable type ground line.

A known type of overvoltage arrester has a diaphragm funtioning as a seal for the housing of the arrester containing the active overvoltage arresting components thereof such as, for example, spark gaps and voltage-dependent resistors. The diaphragm is supposed to rupture, due to a shortcircuit, for example, when the arrester is overloaded and should thereby relieve the housing of the resulting strong pressure. Such a diaphragm may be provided together with a deflection plate in order to direct or conduct the escaping gas in order to ignite a light are outside the housing of the arrester, between voltage-conducting components. The light arc relieves the arrester from conducting current. This type of overvoltage arrester may further comprise a device for disconnecting the ground line. Such a device is actuated upon the rupture of the diaphragm and is described in German Published application No. 1,563,533.

It is the object of the invention to provide an overvoltage arrester having a disconnecting device for the ground line, which is of particularly simple structure and very economical in manufacture.

An overvoltage arrester has a diaphragm which seals the interior of the housing of the arrester and a deflection plate for directing escaping gas. In accordance with the invention, the overvoltage arrester comprises an ejectable type resilient body of cup-shaped sheet metal configuration ejectably mounted in the deflection plate in operative proximity with the diaphragm for affixing a ground line to the arrestor. This is a simple and space-saving structure, since no intermediate members are required, other than the diaphragm and the sheet metal resilient body.

It is preferable to locate the sheet metal resilient body so that its bottom faces the housing or interior of the arrester, and to position the diaphragm a slight distance above the bottom of the resilient body. The diaphragm is in operative proximity with the resilient body of sheet metal over a large area or has a-large area action over said sheet metal body and can rapidly press said sheet metal body out of the deflection plate. The bottom of the resilient body has a configuration which deepens in the direction of escaping gas from the housln order that the invention may be readily carried into effect, it will now be described with reference to the accompanying drawing, wherein the single FIG- UlRE is a schematic diagram, partly cutaway and partly in section, of the lower part of an embodiment of the overvoltage arrester of the invention utilized in medium high voltage systems.

The housing l, which may comprise ceramic material, houses a plurality of active overvoltage arresting components such as, for example, a stack of quench gap assemblies 2 which brace against contact bridges 3 and a lower support plate 4. The support plate 4 is provided with holes 5 to create a passage for gases which occur during overloading of the overvoltage arrester. The support plate 4 is enclosed by a ring 6 which rests upon supports 7of the deflection plate 10.

A diaphragm 11 is inserted between the ring 6 and the support plate 4 and seals the interior of the housing 1 from the outside. The deflection plate 10 is affixed to the housing 1 by clamps, cock bolts or tripping components 13, bolts 14 and nuts 15. A sealing ring 17 is placed between the diaphragm l1 and the front surface 16 of the housing 1 in order to provide a sound seal for the interior of said housing and thereby for the overvoltage arrester.

The deflection plate 10 has an opening 20 therein into which a resilient body 21 of cup-shaped sheet metal configuration is inserted. The resilient body 21 has a bottom 22 of substantially or slightly conical configuration. A socket 23 is affixed to the retracted bottom 22 of the sheet metal body 21 and functions as a terminal connecting point for a ground line 241 to the overvoltage arrester.

The FIGURE illustrates only a slight distance 25 between the diaphragm 11 and the bottom 22 of the sheet metal body 21. If the diaphragm 11 is pushed toward the sheet metal resilient body 21 when an over-pressure occurs in the housing 1, it exerts a force on said sheet metal body which ejects said sheet metal body from the opening 21) of the deflection plate 10. This is greatly aided by the fact that the emerging gas jet strikes the sunken bottom 22 of the resilient body 21, thereby exerting a ramming pressure against said bottom and said body. The gas which escapes during the rupture of the diaphragm 11 is directed, released or expelled through an opening 26 formed through the deflection plate 10. The gas is directed in the direction of an arrow 27 and can ignite an arc in a known manner, which then relieves the overvoltage arrester. The ejection or release of the ground line 24 with the ejection of the sheet metal body 21 creates a visible open ground circuit and indicates the inoperative or useless condition of the arrester.

There are many possible embodiments of the design of the cup-shaped sheet metal body 21. Depending on the quality of the material being used, the desired resiliency or spring action may be obtained with an uninterrupted edge or with an edge which is divided into resilient fingers. The resiliency or springiness may also be affected, for example, by holes or slots worked into the edge of the sheet metal body 21. The bottom 22 of the body 21 may also have a shape which is more or less arched instead of the conical configuration shown in the FIGURE, or may more closely resemble a flat bottom. A specific depression in the direction of the escaping gas is of advantage, however. A relatively small distance between the diaphragm 11 and the bottom 22 of the body 21 which permits a direct action of said diaphragm on said body, without intermediate components, is also essential.

While the invention has been described by means of a specific example and in a specific embodiment, we do not wish to be limited thereto, for obvious modifications will occur to those skilled in the art without departing from the spirit and scope of the invention.

We claim: v

1. An overvoltage arrester having a housing, a plurality of active overvoltage arresting components in the housing, a diaphragm sealing the interior of the housing and a deflection plate adjacent the housing for directing escaping gas, said deflection plate being located directly opposite said diaphragm at a side of said diaphragm located opposite the side at which said arrestwherein the resilient body has a bottom having a configuration which deepens in the direction of escaping gas from the housing.

4. An overvoltage arrester as claimed in claim 2, wherein the bottom of the resilient body is located directly below the diaphragm.

5. An overvoltage arrester as claimed in claim 3, wherein the bottom of the resilient body is of substantially conical configuration. 

1. An overvoltage arrester having a housing, a plurality of active overvoltage arresting components in the housing, a diaphragm sealing the interior of the housing and a deflection plate adjacent the housing for directing escaping gas, said deflection plate being located directly opposite said diaphragm at a side of said diaphragm located opposite the side at which said arresting components are located said overvoltage arrester comprising an ejectable type resilient body of cup-shaped sheet metal configuration ejectably mounted in the deflection plate in operative proximity with the diaphragm and having means affixing a ground line to the arrester.
 2. AN overvoltage arrester as claimed in claim 1, wherein the resilient body has a bottom facing the housing and located directly adjacent the diaphragm.
 3. An overvoltage arrester as claimed in claim 1, wherein the resilient body has a bottom having a configuration which deepens in the direction of escaping gas from the housing.
 4. An overvoltage arrester as claimed in claim 2, wherein the bottom of the resilient body is located directly below the diaphragm.
 5. An overvoltage arrester as claimed in claim 3, wherein the bottom of the resilient body is of substantially conical configuration. 